This invention relates to a developing method of electrostatic latent images formed on a surface of electrostatic latent image carrier with charged toner in an uniformly thin layer formed on a toner transporting member.
Electrostatic latent images are formed, first, on a surface of a photosensitive member in the electrophotographic formation of copied images. Then, the electrostatic latent images on the surface of the photosensitive member are provided with charged toner by a developing device to develop the electrostatic latent images (or make the electrostatic latent images visible). The resultant toner images are transferred and fixed onto a copying member such as copying paper.
In a developing method of electrostatic latent images as above mentioned, in particular, in an one-component developing method using non-magnetic toner, it is important to provide a surface of a photosensitive member with charged toner in an uniformly thin layer.
In a conventional one-component developing method as disclosed, for example, in Japanese Patent Laid Open No. 143831/1977, a surface of elastic developing roller are provided with non-magnetic toner, the non-magnetic toner is pressed against the roller by a blade to charge the toner and form a thin layer of charged toner around the outersurface of the roller, and toner images are formed by contacting directly the charged toner in a thin layer with a surface of photosensitive member.
In a conventional method as above mentioned, the smaller the particle sizes of toner are, the easier the toner are selected and consumed (referred to as "particle size selecting phenomenon" hereinafter), resulted in a change of distribution of particle sizes of toner. Consequently, when toner are used for a long time, image qualities change (deteriorate).